PROBLEM TO BE SOLVED: To provide a nutritious liquid culture produced by utilizing seafood processing by-products. SOLUTION: The liquid culture includes seafood processing by-products containing fish bone as main ingredients, and is obtained by using mixed culture media enriched in sugar and nitrogen; and culturing microbial associates including lactobacillus or acidophilic bacteria existing together with yeast residing in the surface layer of the culture media; making the culture liquid have≤pH4.0 and degrading the fish bone to be dissolved in the culture liquid. The liquid culture for nutritious additive is used as drinking additive, fertilizer or a plant-vitalizing agent. COPYRIGHT: (C)2010,JPO&INPIT